It is common practice for communications systems to translate information to be transmitted into a more suitable form for transmission over a communications channel. This encoding operation may be optimized in response to particular channel characteristics, such as available bandwidth, latency, noise, etc. The encoding and subsequent decoding operations may require considerable hardware resources or computational power, in particular in cases where the encoding produces longer code words.
An example of such codes are the so-called constant weight codes or low weight codes, which may briefly be described as codes in which the number of “1” bits per code word is low. These low weight codes have several applications. One of these applications is on-chip or chip-to-chip communications where the low “1” density translates into fewer signal transitions, minimizing channel crosstalk and simultaneous switching output (SSO) noise. In some bus communication schemes, power can be saved by employing constant weight or low-weight codes. Low weight codes may also have applications in volatile and non-volatile data storage.
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